已知:3m-5n=0,求m/(m+n)+m/(m-n)-m^2/(m^2-n^2)的值

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已知:3m-5n=0,求m/(m+n)+m/(m-n)-m^2/(m^2-n^2)的值

已知:3m-5n=0,求m/(m+n)+m/(m-n)-m^2/(m^2-n^2)的值
已知:3m-5n=0,求m/(m+n)+m/(m-n)-m^2/(m^2-n^2)的值

已知:3m-5n=0,求m/(m+n)+m/(m-n)-m^2/(m^2-n^2)的值
合并多项式,(m/m+n)+(m/m-n)-(m^2/m^2-n^2)
=2m^2/(m^2-n^2)-(m^2/m^2-n^2)
=m^2/(m^2-n^2)
将 m=5n/3代入得,(5n/3)^2/[(5n/3)^2-n^2]=(25/9)/[(25/9)-1]=25/16